Army called to assist as Canterbury thrashed by snow and floods, with almost entire month of rain falling today in Akaroa

Canterbury is being thrashed with heavy rain, flooding and snow, with the army called in to assist Selwyn residents as floodwaters rise. 

A Severe Weather Warning by MetService as a low to the east of Canterbury brings southerly rain. 

The Heavy Rain Warning stretches from Fairlie northwards up to Culverden, with the heavy rain expected to ease off north of Christchurch this afternoon.

The Heavy Snow Warning is in place for the same area, with snow to 500 metres expected until early this evening. 

"People in the area, especially trampers, are advised to look out for rapidly rising rivers and streams, and localised flooding and slips," MetService reported.

"Heavy snow is likely to cause disruption to transport and place stress on livestock."

Flooding and rain has also hit Christchurch and Akaroa, with some roads closed with surface flooding and up to 50mm of rain expected to fall by this evening.

NIWA posted on Twitter Akaroa had 114.6 mm of rain in the last 12 hours, which is 93 per cent of the normal amount to fall for the whole month of August.  

The Christchurch City Council has deployed pumps in Flockton, Bromley and Southshore as a precaution.

Residents in low lying areas are being advised to contact the council if they're concerned about rising water levels.

Fairfax reported the army will be assisting Selwyn residents as river levels are monitored across the region. 

"An emergency operations centre had been set up in Rolleston, and council teams were monitoring river levels across the district," Selwyn District Mayor Sam Broughton told Fairfax.